Variable message signs are used on roadways to inform motorists of hazards and traffic conditions. Each variable message sign has a controller that has a direct communication link to a Remote Management Station (RMS). Often the direct communication link is a fiber optic link, which is expensive to install and requires an expensive fiber modem. In addition, the direct communication link requires an overhead intensive communication protocol such as NTCIP (National Transportation Communication for ITS [Intelligent Transportation Systems] Protocol). In addition, each of these direct communication links and its associated hardware are potential failure points as is each of the controllers. In addition, many variable message signs contain information from a wide variety of sources. For instance, a sign may contain toll information, travel time and exit information. The sources for each of these messages may originate at different locations. Presently, it is necessary to combine this information at a remote management station and when an update to any of the messages is received the sign must be rewritten in its entirety. This process is cumbersome for the Remote Management Station, requires system coordination, and is prone to error.
Thus, there exists a need for a sign controller system that is less expensive to install and operate and increases the reliability for variable message signs and changeable sign